As an important unit in the fix-orthodontic technique, a bracket is an orthodontic appliance for correcting deformity of the teeth. The bracket can be bonded directly to the surface of dental crowns, and various types of orthodontic forces can be applied to the tooth by an arch wire via the bracket, so as to realize orthodontic treatment.
At present, the tie wings, bracket slot and bracket base included in the bracket around the world are all integrated as one, the arch wire used for orthodontic treatment is fixed inside the bracket slot, and the tooth and the bracket may slide as a whole along the arch wire. A certain angle is formed between the bracket slot and the bottom of bracket, this angle and the inclination can determine the labial-lingual (labial-palatal) inclination (torque) of teeth, the axis inclination (tip) at a mesial direction and a distal direction, and the rotation of tooth body. There are many standards about the angle and the inclination of the bracket slot around the world, however, each type of data has its advantages and disadvantages, thus argument about qualities of each data never stops. All bracket slots of traditional brackets are fixed at present, and for a set of brackets, different brands or producers may use different data of the bracket slot. Orthodontists are faced with various patients requiring orthodontic treatment, so a bracket with one type of data may be hard to meet the requirement of orthodontic treatment.